Coke oven structure



Nov. 21. 1939. J. BECKER COKE OVEN STRUCTURE Filed May 7, 1937 6 Sheets-Sheet 1 INVENTOR.

Jose/w BEcKE/a.

ATTORNEY."

Nov. 21, 1939. J. BECKER COKE OVEN STRUCTURE Filed May 7, 1957 6 Sheets-Sheet 2 E 5 Y mm m 3 WWW M Nov. 21, 1939. J. BECKER COKE OVEN STRUCTURE 6 Sheets-Sh 4 Filed may 7' 1957 INVENTOR. JOSEPH Backs/9,.

I TTORNEY.

J. BECKER Nov. 21, 1939.

COKE OVEN STRUCTURE Filed May '7, 1937 6 Sheets-Sheet 5 I v1 6 01 9 0, 1 0 01 My HAM/9 0 629 0 1 70 1 mo uo 1N ENTOR.

JOSEPH g'sc/vsla.

BY v A lTORNE Y.

Nov. 21, 1939. J. BECKER COKE OVEN STRUCTURE Filed May '7, 1937 6 Sheets-Sheet 6 INVENTOR. jbs PH flee/a152,.

ATTORNEY.

Patented Nov. 21, 1939 COKE OVEN STRUCTURE Joseph Becker, Pittsburgh, Pa assignor it Koppers Company, Pittsburgh, Pa., a corporation 7 of Delaware Application May 1, 1931, Serial No. 141,203 3 Claims. (01. 202-268)- The present invention relates to horizontal coking retort ovens and more generally to those ovens having coking chambers alternately disposed with heating walls that are provided with 5 vertically extending heating flues and therebeneath regenerators that course substantially in parallelism with the heating walls. The invention is more specifically concerned with such combination coking-ovens of the above-mentioned type as flow the heating gases through the flued heating walls in a manner requiring that the regenerative spaces which extend lengthwise of the heating walls shall be divided into a plurality of two or more compartments by a cross-wall or 5 cross-walls that separate the inflowing from the outflowing regenerator compartments. Expansion joints are necessarily provided in these crosswalls during their construction to allow for the subsequent expansion which the brickwork undergoes while it is being elevated to operating temperatures, and more especially in combination ovens having a gas-flow system of this type,

it is of utmost importance from considerations of thermal economy and for the preservation of the integrity of the coking retort structure that said regenerator cross-walls be maintained-absolutely impervious to transfer of gases therethrough.

The gaseous pressure in the inflowing regenerators is relatively higher than that in the outfiowing regenerators, and consequently at such times as coking retort ovens of the class under consideration are being operated as gas-ovens,

that is, when fuel gas of low thermal content is being flowed into some of the inflow regenerators for the purpose of preheating it, the possibility arises that some of the fuel gas may short-circuit the heating fines and flow directlv into the combustion-products regenerators if the expansion joints in the cross-walls separating the inflow and outflow regenerators have not been tightly sealed by their expansion during that time the new structure was being elevatedto operating temperatures. Such circumstances will naturally result in reduced thermal efficiency for the structure and may even seriously damage the checkerbrick and the re enerator walls and engender conditions that will become accumulatively aggravated with continued operation.

Those regenerator walls that extend longitudinally of the'ovens are normally constructed without expansion joints except at points adjacent their upper parts where they ioin with the brickwork of the oven floors and they can therefore be constructed as well-mortared and unjointed structures because in the heating-up of the finished structure ample space is available for them to expand into without subjecting other features of the oven to disruptive stresses. When, however, the gaseous flow-paths of a particular 5 underfiring system require, for the establishing of those flow-paths, that gas-tight cross-walls be disposed at intervals transversely of the regenerative spaces, it is necessary to provide unmortared expansion joints which will accommodate the ex- ,pansion of the cross-walls themselves as well as the lateral expansion of the longitudinal regenerator walls and in as much as these expansion joints are unmortared, their proper closing and sealing dependsentirely on the exact expansion of the brickwork into the joint-voids and also upon a precise regulationof the expansion of all parts of the battery structure. If the expansion stresses around the joints are not accurately directed and the growth of the brickwork not pre- 20 cisely that which has been calculated for, during all periods of the heating-up process, or if the brickwork suflers small amounts of overor under-expansion resulting from lack. of homogeneity in the materials employed, cracks and 25 fissures may be left or produced through which incipient and thereafter increasingly serious short-circuiting of gases may take place between fuel gas and waste gas regenerators; a situation which, in consequence of the relatively high pres- 30 sure differential between the gases of the inflow and outflow regenerator compartments, will result in excessive temperatures of the combustionproducts leaving the structure and even in fluxing of the brickwork. 35

Among the objects of the present invention is the provision of method and means whereby all these disadvantages arising from the necessity of having expansion joints in regenerator crosswalls can be simply and satisfactorily avoided. 4% By means of the hereinafter disclosed improvement it is assured that such cross-walls will be adequately and easily sealed against any potential cross-leakage, and for its practise structural innovations are provided which allow easiest 45 accessibility to them from the exterior of an oven or a battery thereof so that the measures provided by the improvement can be simply carried out.

The invention has for further objects such 50 other improvements and such other operative advantages or results as may be found to' obtain in the methods or apparatus hereinafter described or claimed.

According to the present improvement, the 55 bricks employed to form the expansion joints of regenerator cross-walls are provided with such configuration that when they are assembled there is purposely formed within the space of said joint, and whether or not its parts have been properly joined together during the expansion undergone in the heating-up step, a vertically extending canal or chamber which extends from the bottom of the cross-wall to the top thereof. In its preferred disposition said vertical canal and its associated expansion joint are positioned by the invention directly beneath the oven floor in the oven structure. Accessibility to this joint-chamber, from the outside, is provided by means of a therewith aligned aperture in the oven floor, said aperture being in turn in alignment with a charging hole at the top of the oven. By thus arranging the charging hole, the oven floor aperture and the joint-canal in substantially a straight line, said joint-canal is accessible throughout its entire length from the top of the oven and it can be filled therefrom with any preferred refractory material which will then penetrate from said canal into any fissures or cracks of the expansion Joint that have not been properly sealed. The aperture in the oven sole is provided with a fitted plug to close it. In the preferred method of practising the improvement, the. canal or chamber, that interrupts the expansion joint, is filled with an appropriate sealing material subsequent to the heating-up period and after the expansion of the oven and the incidental movements and stresses in the brickwork have come to equilibrium and rest. By flowing into and around those portions of the expansion joint which may not have been closed ofi and sealed during the expansion process and also by flowing therefrom into any fissures or cracks that may have developed there-adjacent for any reason, the sealing material will plug and permanently close all such openings thereby assuring a gas-tight wall throughout its entire height.

In those ovens having a supporting mat that lies directly on the ground surface, accessibility to the above-described joint-canals cannot be provided from beneath the oven or a battery structure, but in those instances where the structure Y rests on piers that provide accessible passageways beneath the battery mat, the joint-canals of the invention can be so formed as to extend down-.

ward through said mat and to open in said passageways, and the preferred sealing material can be forced upward thereinto from their lower parts. When such means of access to the Jointcanals are available, it is obvious that the need of providing alignment between the charging holes, the oven-floor apertures and the joint-canals does not obtain, and the expansion joints of the regenerator cross-walls can be placed therealong substantially wherever preferred since the opening through the mat providing accessibility thereto, can be optionally located with due regard for the regenerator sole-channels.

In the accompanying drawings forming a part of this specification and showing for purposes of exemplification a preferred apparatus and method in which the invention may be embodied and practised but without limiting the claimed invention specifically to such illustrative instance or instances:

Figure 1 is a vertical sectional view taken crosswise of a battery of ovens of the type such as that above-specified and equipped with the improvements of the present invention, the view being taken through a coking chamber and partially through a heating wall as indicatedlespectively by .the lines IV--IV and III-III of Figure 2;

Figure 2 is a view in longitudinal section of the coke oven battery of Figure 1 taken along the line II-II of Figure 1;

Figure 3 is' a partial vertical sectional view taken along the line III-III of Figure 2 and showing the arrangement of the fines in the heating walls of an oven provided with underjet underflring and having a gas-flow system with which the present invention is especially adapted to be combined;

Figure 4 is a partial vertical sectional view taken along the line IV-IV of Figure 2 and showing the alignment of the expansion jointcanals and the charging holes, through which coal is introduced into the oven, as provided by the invention along with the apertures in the oven floor through which accessibility to the expansion joints is made possible from the top of the oven as well as the mat-ducts through which said joints are accessible at their lower end in batteries having accessible passageways be I neath;

Figure 5 is a horizontal section taken along the line VV of Figure 2;

-Figure 6 is an enlarged fragment of Figure 5 showing in detail the arrangement. of the brickwork both of the regenerator walls that course longitudinally of the oven and the regenerator cross-walls in which the present improvement'is incorporated; and

Figure 7 is ,a view taken along the line VII-VII of Figure 1.

The same characters of reference designate the same parts in each of the views of the drawings.

For purposes of exposition, the present inven tion-is shown in combination with a' combination coke oven battery of the so-called underjet type in which when utilizing rich fuel gas that does not require a preheating step for its effective combustion, said rich gas is carried into the flame flues, from a distribution system located in accessible passageways beneath the battery-supportingmat, by means of ducts that rise vertically both through said mat and the longitudinal walls of the regenerators to terminate in the lower part of the vertical fiues. In the embodiment shown in the drawings, the vertical heating flues of each heating wall are communicably' connected with two of the regenerator spaces that extend in parallelism with the heating walls. Each of these longitudinal regenerators is divided by three vertical cross-walls into four separate and individual compartments that each have individual sole-channels extending to the battery faces, and the fiues of each heating wall are also divided into four equal groups, all the fiues of each group being communicably connected at their lower' ends by ducts with two of the correspondingly positioned regenerator compartments lying side-by-side gitudinal regenerative spaces that extend the fully 2,180,857 stack. At such times as-the oven battery is operated as a gas-oven-and therefore underflred with an extraneously produced lean gas, such as producer gas, the alternate endwise abutting pairs of regenerator compartments on each side of the lengthwise median plane of the battery are arranged to alternate in carrying fuel gas to heating flues and products of combustion to the atmosphere while the intermediate pairs of endwise abutting compartments are arranged to carry combustion air and products of combus tion alternately to and from heating flues.

From the above-given description of the system of gaseous flow in the battery of ovens shown in the drawings, it is evident that the cross'walls in the longitudinal regenerative spaces serve to isolate the abutting up-fiow and the down-flow compartments from each other, and in as much as the up-flow compartments carry combustible gases and .the down-flow compartments carry combustion-products at a relatively high pressure diiferential, it becomes apparent, when the battery is operated as a gas-oven, that it is of greatest import that said cross-walls be absolutely gas tight in order to avoid the diverting of unburned fuel gas from the higher pressure up-flow compartments into the lower pressure down-flow compartments where, upon combustion, the leaked gas would elevate the temperature of the waste gases and thus decrease the thermal efliciency of the structure and eventually could lead to serious injury of the brickwork.

By the present invention, a new and useful improvement in regenerator cross-wall construction is furnished which assures to the coke oven builder a gas-tight wall for the endwise abutting regenerator compartments between which there is normally a difierential gas pressure. By means of this improvement it is now possible to seal the expansion joints, necessarily provided in the cross-walls in order to accommodate their expansion during the period the brickwork of a new battery is being raised to operating temperature, after that expansion has taken place so that any detrimental effects which might result from inadequate closing of the joints can be entirely obviated.

Referring to the drawings: the elongated coking chambers In extending crosswise of the battery are arranged in alternation with heating walls H. The heating walls are divided into a plurality of vertically disposed heating flues which communicate at their upper ends through regulable openings with a horizontal flue. The heavy supporting or pillar walls l2 which extend crosswise of the battery serve to support the heating walls that form the sides of the coking chambers. The spaces between the pillar walls form the lonlength of the oven, and they are filled with checker-bricks from one face of the battery to the other, and each flue of a heating wall is communicably connected at its lower end by duets with the two regenerative spaces positioned therebeneath-on opposite sides of the same pillar wall. Each of the longitudinal regenerative spaces is divided into four separate compartments consisting of outer and inner compartments respectively l4, l5, by three regenerator cross-walls I! that extend the entire height of the regenerative spaces and close off all communication between abutting compartments except by way of the heating flues and the horizontal flues. The regenerator compartments are each provided with individual sole-flues that reach to the faces of the battery and there communicate with valved flow-boxes adapted to regulate the flow of-heating media into the regenerators. The two outer rows of regenerator compartments I4 have the shorter sole-channels I'I whereas the two inner rows of compartments I! have the longer sole-channels i8 and all said sole-channels are provided with ducts I! for uniformly distributing heating media over the checker-bricks above them.

In the accessible passageways 20 beneath the battery-supporting met 21 is positioned the rich fuel gas distribution system which comprises the arterial distribution main 22 that communicates with a reservoir of rich gas outside the battery structure and from which main riser-pipes 23 branch to the two distributor headers 24, 25, provided for each heating wall. The multiple-ways cock 26 is connected to a reversing cable 21 by means of crank 28 so that the flow of rich fuel gas can be directed in alternation to headers 24, 25, that respectively carry rich fuel gas to-the outer and inner flue groups. The vertical ducts 28'of the pillar walls l2 serve to carry rich gas to the heating flues individually from the distributor headers- The median plane G-G extending lengthwis of the battery divides its regenerative flue systems into two substantially symmetrical parts of which each is capable of operation independently of the other. Those heating fines of each heating wall that are positioned on the same side of said plane GG are divided for gas-flow purposes into two groups that are interconnected at their upper ends, through regulable openings 3| having sliding bricks IS, with a horizontal flue 33 that is individual to an adjacent inner and outer flue group. The-flues of the outer and inner groups thereof, comprising respectively the flues 3|, 3Ia, are each connected by means of ducts 32 respectively with two of the regenerative compartments ll, l5, correspondingly positioned in respect of the plane G='G and on opposite sides of a pillar wall. By means of this construction there is no intermingling of the heating media or their combustion-products between opposite battery sides.

The flow boxes for regulating the quantities of gases entering and leaving the regenerator-compartment sole-flues are all adapted for communicably connecting said compartments and the heating flues with both the atmosphere and the waste-heat tunnels 34, whereas those flow boxes that communicate with the alternate pairs of endwise-abutting regenerator-compartments positioned on the same side of the plane G-G are further adapted to introduce fuel gas of low thermal content into each of the so-abutting pairs thereof individually and in alternation, when it is preferred to heat the battery with a preheated lean gas that is flowed into the sole flues from the lean gas mains 35.

At such times as the battery in which the instant invention is embodied is operated as a coke-oven, that is, when it is being heated with such gas as is produced in the carbonization process, rich gas is flowed from the arterial main 22, along the distributor header 24 by proper regulation of cock 25. The rich gas then rises through ducts 29 in the regenerator pillar walls l2 and eventually into all the heating flues of the outer flue groups where it is burned with air that has been introduced through air lids 36 into the shorter sole-channels l1, whence it rises through the regenerator compartments for preheating and thence into the heating flues 3| through canals 32. The, burning gases rise through flame flues 3| and enter horizontal flue 33 which is provided with a larger cross-section at those points therealong where it must accommodate the larger volumes of combustion-prod- As the combustion-products flowalong both the horizontal fluesv 33, toward the median plane GG and away from the tops of the flame flues, they are distributed into the upper ends of the non-burning flues 3 la wherein they flow down into the regenerator compartments l5 and thence to sole-channels i8 and waste-heat tunnels 34 through flow-boxes and '4l (Figure 5). At preferred intervals, the direction of-flow of the heating gases in the regenerator compartments and heating flues is reversed and the inflowing regenerator compartments become the outflowing ones and the flame flues become the: nonburning flues, and vice versa. I a

When the battery is operated-as a gas oven and is therefore ,underflredwith lean gas that is preheated in the regenerator compartments, the lean gas, such as producer or.blast furnace gas, is introduced into each regenerator of the alternate pairs of endwise-abutting regenerators located on ,the'same side of the plane G--G in alternation from the lean gas line 35. That is, for example, during one direction of gaseous flow in the underfiring system, lean gas will be introduced into the alternate regeneratoncompartments M of the outer rows thereof from the lean gas mains 35 through flow boxes 38, while combustion air is being simultaneously introduced into the, intermediate compartments from flow boxes 39. ,.With such direction of flow in the heating fiue and regenerative system, both inner rows of regenerative compartments I5 are filled with combustion products which are withdrawn therefrom through the sole-channels l8 and the therewith connected flow boxes 40 and 4| to the waste heat tunnel 34. In the reverse direction of flow, lean gas is introduced into the alternate regenerator compartments l5 of each inner row thereof and combustion air into the intermediate compartments respectively through the flow boxes 40 and 4| and the combustionproducts are assembled in all of the outer compartment rows and are flowed into the waste heat tunnels through sole-flues l1 and flow boxes 38, 39, In other words, in the battery shown in the drawings, of the four regenerator-compartments comprising one regenerative space that is coextensive with a heating wall, two compartments symmetrically disposed with respect to the vertical plane GG are filled during a given period with products of combustion from which heat is being recovered while the remaining two compartments are filled with either lean gas or combustion air being preheated.

From the above-given description of a method of operating as a gas-oven the battery in which the improvement provided by the present invention is embodied, it becomes clear that the two outer cross-walls l3 of the three such walls located in a complete regenerative space, have fuel gas and itscombustiomproducts on opposite sides thereof during both reversal periods of the regenerative heating cycle. The differential between the pressures of the fuel gas and its combustionproducts in their respective compartments, as is 'well-known, is such that, if the cross-walls 13 are not gas-tight, fuel gas will by-pass the heating fines and flow directly into combustion-products compartments, and in so doing not only give rise to heat losses but also endanger the integrity of the cross-wall and the checker-brick. The danger of cross-leakage through the longitudinal walls of the regenerative spaces is less likely to arise since such walls are generally of more rugged construction than the cross-walls because they are the principal support of the weight of the upper part of the battery and it is highly desirable that said cross-walls be no thicker than necessary so as to conserve as much regenerative space as possible for the checker-brick.

. During their construction, the cross-walls 13 are provided with expansion joints 44 so that the expansion the brickwork comprising them undergoes during the time, the new structure is being brought to operating temperature, may be easily taken up without disturbing the alignment of the brickwork in either the longitudinal or the cross-walls. The available room for expansion in the provided joints must be relatively accurately determined with consideration for the materials .20

employed in their construction and for the temperatures obtaining in the brickwork at various wall heights during operation, else there can be no assurance that the joints will expand in such manner as to give a continuous and gas-tight wall. In addition, the stresses arising throughout the-battery during the heating-up period must be accurately directed so that opposite faces of the joint bricks will slide into contact as parallel surfaces and .not in angular displacement else damage of the engaging surfaces may result which will prevent proper contact taking place during the expansion period.

All these problems and eventualities are readily and definitely solved by my present improvement which provides method and means whereby the expansion joints in regenerator cross-walls can be definitely sealed beyond all question after the battery structure has been brought to operating temperature and the cross-walls have been substantially fully expanded.

According to the present invention, the continuity of the expansion joint 44 shown in the regenerator cross-walls l3 in Figures 2, 5, 6, which for purposes of exposition is shown in the drawings to be of the ship-lap type although the advantages ofiered by the improvement can be realized in expansion joints having a variety of designs, is interrupted in such manner as to form a vertically disposed canal or hole 45 of substantially greater cross-section than that of the joint itself, the bricks adjacent the joint being of appropriate configuration to form the same. The canal 45 should be of such cross-section that when the masonry of the cross-wall has been fully expanded said canal will be of adequate crosssection to permit a preferred sealing material being introduced thereinto and it should preferably also extend from at least the bottom of the lowest brick tier of the joint upwards to the top .of the cross-wall. The invention also provides accessibility to the joint-canal from outside the battery structure by means of a therewith aligned perforation 46 in the brickwork of the floor of the coking chamber, said perforations being in turn in alignment with charging holes 41 through which coal is introduced into the coking chamber Hi.

;In those instances where the improvement is incorporated in a coke oven battery having accessible passageways beneath its supporting mat, as shown in the drawings, the joint-canal 45 is preferably extended downward through said mat by means of a communicating mat-duct in which is supported a pipe 48 that is closed at its lower end by means of a pipe-cap 49. In such oven batteries, the invention therefore provides accessibility to the joint-canal from either the top or from below the battery. It is of course obvious, in those of its applications where accessibility to the joint-canals is possible from beneath the supporting mat, that that feature of the invention which provides means for effecting easy access to said canals from the top of the battery, 1. e., the aligning in a vertical plane of charging holes and perforations in the oven sole bricks with the jointcanals, may be dispensed with if preferred, and the charging holes may be arranged according to other preference, but for those installations however, where the supporting mat I3 is at ground level, said feature furnishes very simple means for reaching the joint-canals from outside the battery structure.

The joint-canals 45 provided by the invention are filled with a refractory sealing medium which may be introduced thereinto either from the top or the bottom. The sealing medium should preferably be of a flowable type not only to facilitate its introduction into the joint-canals but also to enable it to seek out and penetrate therefrom into any chinks, crevices, fissures and the like that may remain open after the brickwork of the cross-walls have been fully expanded. In as much as said joint-canals are preferably of from about threetto four inches in diameter, they are adapted for filling with a wide variety of refractory substances which are suitable for preventing the flowing of gases across said cross-walls at the gas pressure differentials normally existing between the regenerator compartments at their opposite sides, and it is consequently not intended to limit their use to combinations with any specific sealing medium. For example, it may in certain instances be preferable to utilize a fine sand, wellground firebrick or the like, whereas in other applications a grouting-like settable or bonding refractory cement or its equivalent would provide important advantages since such materials would flow from the joint-canals into associated cracks and crevices and consolidate with the brickwork in such manner as to change the cross-wall into a continuous unbroken whole. A viscous or a plastic medium may be forced under pressure into the joint-canals either from the top or the bottom thereof and if the canals are completely filled with a material of this nature and in such manner that the column exerts a hydrostatic head, this head will advantageously force the sealing medium into the smaller associated voids to seal them before the mortar has set. In still other instances when employing certain refractory cements, it may be found advantageous to build up the refractory seal in small increments in situ, as for example by intermittently flowing small amounts of a dry cementing material into the joint-canals and mixing it in place with a jet of water thereby gradually filling the column with the preferred medium. It is of course obvious that the joint-canals should be filled only after the brickwork of the cross-walls has been expanded when employing sealing media that consolidate with the masonry, so that there will be no obstruction in the joint that would operate as an obstacle to its expansion. By way of example, in ovens having regenerators built entirely of silica bricks, I prefer to use a cement containing about 92-94% SiOz and 4-5% A1203, the remainder comprising basic materials such as lime, alkali metals and the like.

The expansion joints 44 should preferably not lead directly from the joint-canals to the regenerative spaces but should be ofiset as shown in Figure 6. Since the greatest dimensional change in the cross-walls during their expansion is a lengthwise one, those portions of the expansion joint that extend transversely of the cross-wall 1 these narrower interstices assist in retaining the' sealing medium in the joint-canals by hindering its flow therefrom even when the walls are cold and unexpanded, thereby making it feasible to fill said canals even during the construction period if a yielding sealing material is employedv that does not materially alter its characteristics at normal temperatures of regenerator operation.

Although in its preferred form the invention disposes the expansion joints and joint-canals adjacent the vertical median of the regenerator cross-walls where they are easily accessible from outside the ovens through the charging holes by means of therewith aligned apertures in the oven floors, it is not intended to limit the disposition of these joints to that specific location for they may be variously positioned therealong and it may be possible to locate the expansion joints adjacent or at the juncture of the cross-walls and the longitudinal pillar walls where they would be accessible from beneath the oven-supporting mat through a mat-duct lying in proximity to the duct communicably connecting the rich gas ducts with the system for distributing rich fuel gas along the heating walls, and at their upper ends they would be accessible, through openings in the brickwork at the bottom of the heating flues, said openings being preferably in alignment with those holes 50 in the top of the battery that are provided for inspection of combustion in the fiues and the adjustment of sliding bricks at the upper ends of said fiues.

The invention as hereinabove set forth is embodied in particular form and manner but may be variously embodied within the scope of the claims hereinafter made.

I claim:

1. A regenerative coking retort oven of the type described, having underneath the plane of the bottoms of the oven chambers and heating walls elongated crosswise regenerative spaces divided into a plurality of countercurrent flow regenerator compartments by a cross-wall extending transversely beneath the carbonization chamber bottoms through said regenerative spaces, in which there is provided an expansion joint for said cross-wall adapted to accommodate its expansion during temperature rise, said expansion joint having therewithin an open sealing canal adapted to receive a sealing medium, said canal extending substantially the entire height of the cross-wall, and a pluggable duct adapted to communicably connect with said sealing canal, one of the upper and lower ends of said duct and canal being located so as to be accessible from outside the oven through one of the upper and lower extremities of the oven so that desired sealing medium can be introduced externally of said oven into said' sealing canal, to cause sealing off of said expansion joint. 4

2. A regenerative coking retort oven according to claim 1, in which a charging hole for intro- 5 ducing carbonizable materials into said carbonization chamber is disposed in substantial alignment with said pluggable duct, said duct being located in the floor of said chamber and also in substantial alignment with said sealing canal,

10 said charging hole constituting an accessible passageway in the oven roof for plugging the canal and duct.

3. In a regenerative coking retort oven battery having a series of alternate horizontal carboniza- 5 tion chambers and intermediate flued heating walls therefor and having therebeneath a plurality of elongated regenerative spaces extending crosswise of the battery, arranged side-by-side and separated by pillar walls that extend in sub- 20 stantial parallelism with the heating walls, said regenerative spaces being divided into a plurality of counterfiow compartments by cross-walls that extend transversely of the pillar walls; each of the regenerator cross-walls being bonded-at both ends thereof to, and free of expansion joints at, the abutting pillar walls, and containing at the middle of the cross-walls intermediate the opposite pillar walls to which they are bonded, a 5 vertical expansion joint separating the wall into two separate sections for expansion longitudinally of the battery during elevation to operating temperatures, each such section comprising a buttressing mass of brickwork integrally bonded tom gether for the full wall width, and free from expansion joints, between the region of the expansion joint at the middle of the wall and the surfaces of the abutting bonded pillar walls; and within each such expansion joint an open joint 15 sealing canal that intercepts the plane of the sliding contact faces of the expansion joint for substantlally the entire height of the expansion joint in the cross-wall for containing refractory sealing media to prevent leakage of gas through said go cross-walls.

- JOSEPH BECKER. 

